1. Field of the Invention
The present invention relates to a method of providing Mobile IP (MIP) functionality for a non Mobile IP capable mobile node. Further, the present invention relates to a switching device for acting as a Mobile IP proxy.
2. Related Background Art
Currently, a user equipment (UE) in a General Packet Radio System/Universal Mobile Telecommunication System (GPRS/UMTS) network keeps its Internet Protocol (IP) address for the whole duration of a session. Here, a session refers to the lifetime of a packet data protocol (PDP) context. This however implies that such user equipment is not able to move from one Gateway GPRS Support Node (GGSN) to another GGSN, even though it may have moved closer to a new GGSN. In the latter case, however, it would be more efficient to route the traffic to the mobile node through the new GGSN.
Moreover, a user equipment is currently provided with an IP address either dynamically, when a PDP context is activated, or statically at the subscription time. With dynamic IP addresses, the user equipment can get an IP address whenever it roams to a visited network and a GGSN will be allocated in the visited network. However, it needs to be noted that even in this case, a new PDP context has to be activated.
If push services besides multimedia services based on the UMTS IP Multimedia Subsystem (IMS) architecture are considered in this case, either dynamic modifications in the Domain Name Server (DNS) are needed (i.e. to be updated to the new IP address associated to the user equipment in the visited network) or the user equipment will not be reachable for such services unless the user equipment first contacts possible future correspondent nodes (CN).